From 44285a16ecc6e43c2121756bd8919ccf9d467396 Mon Sep 17 00:00:00 2001
From: ZhangYu <zhang.yu61@zte.com.cn>
Date: Wed, 16 Nov 2022 14:13:39 +0800
Subject: [PATCH] Add test for cmd/kubeadm/app/constants/constants.go

Add test for cmd/kubeadm/app/constants/constants.go
---
 cmd/kubeadm/app/constants/constants_test.go | 61 +++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/cmd/kubeadm/app/constants/constants_test.go b/cmd/kubeadm/app/constants/constants_test.go
index ae991172e46..3b1dabb3912 100644
--- a/cmd/kubeadm/app/constants/constants_test.go
+++ b/cmd/kubeadm/app/constants/constants_test.go
@@ -350,3 +350,64 @@ func TestGetAPIServerVirtualIP(t *testing.T) {
 		})
 	}
 }
+
+func TestGetDNSIP(t *testing.T) {
+	tests := []struct {
+		name          string
+		svcSubnetList string
+		expected      string
+		expectedError bool
+	}{
+		{
+			name:          "valid IPv4 range from single-stack",
+			svcSubnetList: "192.168.10.0/24",
+			expected:      "192.168.10.10",
+			expectedError: false,
+		},
+		{
+			name:          "valid IPv6 range from single-stack",
+			svcSubnetList: "fd03::/112",
+			expected:      "fd03::a",
+			expectedError: false,
+		},
+		{
+			name:          "valid <IPv4,IPv6> ranges from dual-stack",
+			svcSubnetList: "192.168.10.0/24,fd03::/112",
+			expected:      "192.168.10.10",
+			expectedError: false,
+		},
+		{
+			name:          "valid <IPv6,IPv4> ranges from dual-stack",
+			svcSubnetList: "fd03::/112,192.168.10.0/24",
+			expected:      "fd03::a",
+			expectedError: false,
+		},
+		{
+			name:          "invalid subnet range from dual-stack",
+			svcSubnetList: "192.168.10.0/24,fd03:x::/112",
+			expected:      "",
+			expectedError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			actual, actualError := GetDNSIP(tt.svcSubnetList)
+			if tt.expectedError {
+				if actualError == nil {
+					t.Errorf("failed GetDNSIP:\n\texpected error, but got no error")
+				}
+			} else if !tt.expectedError && actualError != nil {
+				t.Errorf("failed GetDNSIP:\n\texpected no error, but got: %v", actualError)
+			} else {
+				if actual.String() != tt.expected {
+					t.Errorf(
+						"failed GetDNSIP:\n\texpected: %s\n\t  actual: %s",
+						tt.expected,
+						actual.String(),
+					)
+				}
+			}
+		})
+	}
+}